Detecting contaminants in air is an important consideration in closed environments, such as manned space crafts and the International Space Station (ISS). It is important to constantly keep track of the air quality in manned spacecraft and the ISS for the safety of the crew as well as any experiments on board. The cabin contains a limited resource of breathable air to sustain life. In order to protect the astronauts, this air must be kept clean from hazardous gases. Hazardous gases or vapors from inside and outside the cabin may leak into the air supply and pose a major threat to the crews' health. A real-time gas detector is desired to notify the crew members immediately when the hazardous gases or vapors become present in the cabin air. Currently, contaminates released into the air supply are monitored by frequently analyzing the cabin air using a variety of technologies including Mass Spectrometry (MS), Differential Mobility Spectrometry (DMS), and Flame Ionization Detection. Often, these detection instruments are coupled to a front-end Gas Chromatograph (GC).
The use of standard, dorm refrigerator-sized GC/MS analyzers for planetary missions would be prohibitively expensive, since they are heavy, slow, and require maintenance. A portable gas analyzer can resolve this issue if it is sensitive enough to detect the required species for the mission. It will also provide the crew with real-time information about an unknown environment, rather than waiting for remote data analysis.
Portable gas analyzers can also be useful in a variety of industrial settings, such as manufacturing facilities that use chemical agents for cleaning, etching, dissolving, etc. as part of the manufacturing process. Portable gas analyzers can also be used in military environments, especially in combat situations where the threat of chemical warfare is present, and at airports, subways, or other public facilities to detect minute amounts of chemical agents that might indicate the presence of chemical warfare agents or other hazardous substances.
A Flame Ionization Detector (FID) is a sensitive detector for hydrocarbons. The measurement is performed due to the chemical ionization of the hydrocarbons in an oxy-hydrogen or air-hydrogen flame. The hydrocarbons can be detected by measuring the resulting ion current. The FID has been extensively used in research and industrial labs to analyze gas samples in tandem with gas chromatographs (GC).
However, none of the reported micro-GC/FID systems were truly portable, and there is an ongoing need for portable, sensitive, and self-contained systems capable of accurately analyzing gaseous species in the air.